Improvement in processes and apparatus for separating silver and other precious metals



2 SheetsSheet 1. A. K. EATON. Process and Apparatus for Separating Silver and other Precious Metals from Lead. No.196,204. Patented Oct.16,1877.

N- PETERS, PHOTO-LITHOGRAPHER, WASHXNGTON, D C.

2'Sheets-Sheet 2.

' Separating Silver and reoious Metals from Lead.

Patented Oct. 16, 1877 A. K. EATON Process and Apparatus for other P No. 196,204.

fig. a.

Fig; 2.

J ",PETERS, PHUlU-UTHOGRAFHER, WASHINGTON, D c- UNITED 'rn'rns ATENT OFFICE.

ASAHEL K. EATON, OF BROOKLYN, NEW YORK.

IMPROVEMENT lN PROCESSES AND APPARATUS FOR SEPARATING SILVER AND OTHER PRECIOUS METALS FROM LEAD.

Specification forming part of Letters Patent No. 196,204, dated October 16, 1877; application filed April 12, 1877.

To all whom it may concern:

Be it known that I, AsAI-IEL K. EATON, of Brooklyn, in the coimty of Kings and State of New York, have invented a new and Improved Process and Apparatus for Separating Silver and other Precious Metals from Lead, which is fully set forth in the following specification and the accompanying drawings, in which- Figure 1 is a vertical section of the machine. Fig. 2 is a plan of the base of the machine. Fig. 3 is a horizontal section, showing the annular trough and the top viewof the bowl. Figs. 4 and 5 are detached views.

This invention relates to the working of silver-lead, and enables me, by mechai iical means,

to concentrate, immediately, cheaply, and completely, the silver with a small portion of the' lead, the great bulk of the latter metal being, at one operation, made practically free from silver, thus dispensing with the prolonged and tedious processes usually conducted by manual labor.

Lead, as produced from argentiferous galena, carries from six ounces to two hundred ounces, or more, of silver per ton of crude silver-lead, and the first step in the separation of these metals involves the elimination of most of the lead in a commercially pure form, leaving,

is introduced into the bowl, the latter having been previously heated to about the meltingpoint of the alloy by means of the furnace g. The bowl is thenset in rotation, the speed being at first moderate and gradually increased.

. The bath of metal, obeying the action of centrifugal force, sinks at the center and rises correspondingly upon the sides of the vessel B,

prefer to use in alloying with the silver, it is' apparent that any other metal that will com bine with it more readily than the lead does, and form an alloy of relatively lighter specific gravity, will serve my purpose as well. I wish to be understood, therefore, as including all such metals as being within the spirit and purpose of my invention.

The tendency of the zinc alloy to remain behind in the vessel is greatly increased by the solidification that-begins to take place as soon as the rotation is commenced, since this gradual consolidation makes the alloy less mobile than the lead. If gold be present, as well as silver, it is better to allow the metal to cool down before rotating until a crust begins to form. Having kept up the rotation imtil most of the lead has been delivered into the circular channel, the speed may be greatly increased. The effect of this increase of motion is to throw out of the remaining pasty alloy an additional quantity of lead, leaving the remainder in the condition of a dry spongy alloy. This stage of the operation obviates entirely the necessity of the process of liquation, which is a necessary and troublesome part of all of the ordinary processes.

The form of bowl used, and which I think preferable, is, as will be seen by the drawings, parabolic, but this is not absolutely essential.

The advantages arising from this invention are as follows:

First, the work of concentration is done very rapidly, and almost wholly by mechanical appliances, instead of by manual labor, as in the usual methods.

Second, by one single operation the mass of the lead ma be se )arated praetieally free from action whereby the isolated lead is caused to y l. a

silver; By the ordinaryinethods it requires, overflow the edge of the containing-vessel,

two or three successivetreatments.V V V I V V leaving the light silver alloy in a concentrated Third, the operation of liquation, as praeeondition, substantially as herein 'set'forthp ticedin all otherpr0eesses,is entirely dispensed 2. Thecombination of the rotating bowl, the: V with, tlnis eliminatingthissource of expenes; annular trough, and the receiving-pan, sub- .What I claim as my invention is stantially as described. 7 V V V 1.'Elhe process of separating silver or other 7 r ASAHEL K. EATON. precious metals from lead, which consists in Witnesses: V V r it t 7 alloying zine with the combined metals and -DANIEL BREED,

then subjecting the molten bath toeentri fugal A.MooRE. 

